The cheering and the hugs exchanged by Israeli and American teams last week at Palmahim Air Force base, south of Tel Aviv, marked a historical turn of events.

For the first time ever, a successful test launch had been carried out of the Arrow 3 missile defense system, designed to stop Iranian long-range ballistic missiles – even those carrying nuclear warheads – in space.

The product of Israeli-American cooperation, and years of research and development led by the Israel Aerospace Industries (IAI), together with the U.S. Department of Defense’s Missile Defense Agency, the successful test represented a leap forward in missile defense technology, and a key development in the ongoing Israeli-Iranian arms race.

Travelling at twice the speed of a tank shell, the Arrow 3 interceptor is carried into space by a missile, which then falls away. The interceptor is actually a space vehicle that carries out several swift maneuvers as it locks on to its target. It then lunges directly at the incoming projectile, for a head-on collision.

At speeds of up to 4000 meters (13,123 feet) per second, the interceptor relies only on its self-generated kinetic energy to destroy the hostile missile, and does not require its own explosives to get the job done.

The successful trial underscores the fact that despite significant political differences that exist between Jerusalem and Washington, defense cooperation between the two countries is today at an unprecedented level.

The first batch of four Arrow 3 batteries is expected to come into service between 2014 and 2016. Four additional upgraded batteries, carrying more interceptors, could be built later.

Israeli and American companies are working together to get the Arrow 3 operational. The technological breakthroughs that allowed for the Arrow 3 to be tested have been led by IAI, but collaboration with Boeing has been significant.

Iran is amassing hundreds of missiles capable of striking Israel, while taking steps forward in its nuclear program. As the Institute for National Security Studies in Tel Aviv has recently noted, Iran has Shihab 3 missiles that put all of Israel in range, as well as the Ghadr-1, which is an upgraded version of the Shihab 3.

Tehran is also developing the Sajjil-2, a two-stage solid fuel missile that can strike targets 2,000 kilometers away. Any of these missiles can be fitted to carry unconventional warheads.

To cope with this ballistic missile challenge, as well as the threat posed by Syrian scuds, some of which have reached Hezbollah, Israel has the Arrow 2 missile defense system in place, which shoots down incoming projectiles in the upper atmosphere.

Once it becomes operational, the Arrow 3 will form another layer of defense over millions of Israelis, thereby giving the Israel Air Force two to three shots at intercepting incoming missile.

“We are in arms race. We hope to be one step ahead, technologically,” said defense source well acquainted with the Arrow 3 program.

As part of the race to protect its civilians, Israel has set up the Iron Dome rocket protection system, which intercepted over 90 percent of rockets from Gaza during last year’s conflict with Hamas .

Other projects under development include the David’s Sling system, designed to stop intermediate rockets and missiles, which are a part of Hezbollah’s arsenal of more than 60,000 rockets.

Despite the progress being made in this field, Israel can never rely solely on defense for its national security. In an unstable region filled with radical non-state actors, collapsing states, and an Iran marching towards nuclear weapons capabilities, defense can only form one part of the plan to keep Israel safe.

The other part involves devastating offensive capabilities, designed to surprise adversaries and throw them off balance, bringing any conflict to a swift conclusion.

Originally published at the Gatestone Institute, under the title, “U.S. Helping Israel’s Defense.”